Bijaksana41/Shutterstock Investing in a soundbar is a surefire way to upgrade your TV audio, and it gives you an easy way to enjoy wireless music streaming, smart home controls, and other features you may not have thought of. When you're buying a soundbar  or any other type of home theater product, it pays to know when the best time of year is to score a great deal or a killer promo. One publication that has a lot of experience tracking the timing of deals is  Consumer Reports (CR), and its experts agree that there are three "best" months for buying a soundbar: November, December, and January. This makes total sense: Both November and December are prime months for holiday sales, with many Black Friday and Cyber Monday deals being held or recurring throughout the season. You'll probably find a wide variety of sales: TVs being bundled with soundbars, soundbars being sold with rear speakers, and so on.…